Lap



L. S. RASMUSEN AND B. CARLSON.

LAP.

APPLICATION FILED FEB. 15 1921.

Patented Sept. 12,1922.

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LAP.

Application filed February 15, 1921. Serial No. M5971.

To all whom it may concern:

Be it known that we Lonancn S. RAs- MUSEN and HERMAN B. (Jamison, citizens of the United States residin at Davenport, in the county of 'cott an have invented certain new'and useful Tmprovements in Laps; and we do hereby declare the following to he a full, clear, and

s mmetrically and aocuratelyexpanded positively and to positivel limit the inward movement of said lap e ements, adjustably.

With the above and other objects in view, the invention consists in the novel features of construction, combination and arrangement of parts hereinafter more fully set forth, pointed out in the claims and shown in the accompanying. drawings in which:

Figure 1 is a side elevation of a lap constructed in accordance with my invention;

Fig. 2 is a longitudinal sectional view taken on the line 2-2 of Fig. 1;

Fig. 3 is a perspective sectional view taken on the line 3-3 of Fig. 2;

Fig. 4 is a transverse sectional view taken on the line H of Fig. 2.

1 Fig. 5 is a transverse sectional view taken through the tubular body member illustrating a slightly modified form of the inven tion; an

Fig. 6 is a similar view illustrating still another form of the invention.

. Fig. 7 is a side elevation illustrating a sli htly modified form of lap body.

n common practice internal la s are mounted at one end in a lathe or dril press and rapidly rotated, the tubular piece of work to be treated is slipped over the lap and moved along the same so that all parts of its interior are treated. Often the work is slightly irregular or rou h and it becomes desirable to have the abra, ing surface yield slightly to accommodate itself to these irregularities. Also'a tubular piece of work is sometimes initially produced of a slze State of? Iowa,

slightly larger or slightly smaller than standard and it is the purpose of our invention to cause thislap to adapt itself to these variations.

Referring now more particularly to the construction of our improved lap, the numeral 1 indicates a tubular body having one end provided with internal threads as shown at 2' to receive the threaded end of a shank 2. Adjustably arranged within the threaded portion 3 is an externally threaded sleeve 4 adapted to be threaded into the opening 3 and mounted upon a rod 5. The rod-5 has formed upon its inner end an expanding plug 6. The inner end of the plug 6 is conical 'inshape as shown at 7 and is adapted to be seated within a conical seat 8 formed in the present instance at the intermediate portion of the. bod 1, but it isto be understood that this conical seat 8 may be arranged at any desired position within the length of the body 1.

The outer end of the sleeve 4 is provided with a polygonal portion 9 where the same maybe readily engaged by a wrench or other tool for tightening the sleeve 4 within the threaded portion 3. The outer end of the rod 5 is threaded as shown at 10 and mounted thereon is an adjusting nut 11. V

Arranged within the body and mounted upon the rod 5 is a coiled spring 12 which is adapted to bear against the plug 6 when t the sleeve 4 is screwed in to expand the body 1 and enlarge its circumference.

It will be noted that the conical seat 8 is provided with slots 13 preferably arranged parallel with'the side walls of'the body 1 and adapted to receive a blade member ll carried by the plug 6. From this it will be apparent that when the sleeve 4 is screwed in against the tension of the spring 12 the plug 6 will be forced further into the seat and expand the wall of the body, but the plug will be held against turning movement by having the blade 14 engaging one of the slots 13 in the conical seat thus assuring positive action of the pointed end of the plug in the seat 8. In order to provide for a predetermined expansion the nut 11 can be rotated on the threaded portion 10 at the outer end of the rod 5 drawing the plug 6 toward the tension sleeve 4: so that when the sleeve is adjusted against the spring a predetermined expansion will take place.

In order to provide for sufiicient resiliency in the body 1, a plurality of longituditain measurement.

nal slots 15 are formed within the body and preferably extend to a point adjacent each end of the body so that the portlon between each end of the body can be readily expanded through the action of the plug 6 Within the seat 8. Should the blade M project beyond' the diameter of the plug 6, the same can be readily inserted through the threaded portion 3 by having longitudinal slots 16 formed within the threaded portions to permit the blade to readily pass through the threaded portion into the exterior of the body 1. for the purpose of inserting a tool adapted for finishing or machining the conical seat 8 in the lap body to a larger diameterthan the plug 6 so that in the event of the lap body contracting it will not bind on the sides of the plug 6. In the general use of our improved lap the tool is tobe inserted into a rotary member and rapidly rotated. Before inserting the tool within the rotary member, the required degree of adjustment for the expansion of the lap is obtained b first rotating the nut 9 which in turn W1 1 rotate the threaded portion 4: and force the plug 6 inwardly expanding the lap to a cer- The nut 11 is then rotated the required amount to draw the plug 6 toward the threaded portion 4: until the exact measurement is obtained upon the exterior of the lap. The tubular work is then brought into position and passed over the free ends of the tool and operated upon so that the expanded center of the tool is moved into contact with all portions of the interior of the tubular piece of work being treated. It will be readily noted that the body 1 can be expanded sufiiciently to cause all theirregularities on the surface of the work to be removed.

In illustrating the use of our improved lap We will assume that a lap measuring .500" is used for la ping out a hole in a bushing which it desired, when finished, to measure .505".' The proper procedure will be to screw the part 4 inwardly until the plug 6 expands the lap to about .507" and then move the plug 6 backwardly away from the seat 8 by adjustment of the nut 11 until the lap would measure 1504 which would be the approximate size for this particular operation.

In Fig. 5 it will be noted that we have illustrated the tubular body member 1 as hexagonal in cross section and each side portion thereof being provided with a longitudinal slot at the same as in the main feature of the invention: It will also be noted in Fig. 6 that we have illustrated still another form of the invention which is rectangular in shape, each of the four sides thereof being provided with the longitudinal slots 6 and it is-to be further understood that this. lap body can be made in various sizes A further use for these slots 16 isshank while in Figure 2 we have illustrated a tapering shank, but it will be understood that the-shank may be of any standard design so ,that the same can be readily fitted to the chuck of a lathe.

In Fig. 7 we have illustrated a slightly modified form of the invention wherein the slots 15 extend in substantially parallelism at an acute angle with respect to the axis of the body instead of parallel with the body.

The laps shown in Figures 5, .6 and 7, it will be understood, are particularly adapted to operate by an endwise movement.

We claim as our invention:

. l. A lap including a tubular body, a conical seat arranged within the body having slots arranged therein, a plug slidable within the body and having a tapering point engaging the seat, a movable sleeve threaded into one end of the body, elastic means disposed between the sleeve and plug whereby adjustment of the sleeve will cause the plug to expand the Walls of the body, and means carried by the plug to engage the slots in the seat for preventing turning movement of the plug during the expansion.

2. A lap including a tubular body having yieldable side walls, a conical seat within the body having slots therein, a plug slidably mounted within the body and having a tapering point for engaging the seat, a rod connected to the plug and extending out through one end of the body, a sleeve mounted upon one end of the rod and threaded into one end of the body, a coil spring mounted upon the rod and disposed between the plug and sleeve a nut threaded upon the outer end of the rod to adjust the tension of the spring, and a blade member carried by the plug and engaging the slots in the conical seat to prevent turning movement of the plug during. the expansion of the body through the adjustment of the sleeve.

3. A lap 'member including a tubular body, a conical seat formed therein, an expansible member arranged within the body;

means carried by the body for causing the walls of the body to expand and enlarge the circumference of the body, and means engaging the conical seat whereby to prevent turning movement of said member while being expanded.

4:. A lap including a tubular body memher, a conical seat therein having slots, a

plug movable in the body and having a iaeaese tapering point engaging said seat, means for forcing the plug against the seat to expand the wall of the body, and means whereby to prevent turning movement of the plug durin the expanding operation.

5. EC lap including a tubular body, having yieldable side Walls, a conical seat Within the body, a plug slidably mounted Within the body and having a tapered oint for engaging the seat, a'rod connected to the plug and extending out through one end of the body, a sleeve mounted upon one end of the rod and threaded into one end of the body and a nut upon the outer end of the rod whereby to move the ping toward or away from the at 6. A lap inciuding a tubular body, having yieldable side Walls, a, conical seat within the body, a plug slidably mounted within the body and having a tapered point for engaging the seat, a rod connected to the plug and extending out through oneend of the body, a sleeve mounted upon one end of the rod and threaded into one end of the body, a nut upon the outer end of the rod whereby to move the plug toward or away from the seat, and means carried by the plug and engaging the conical seat whereby to prevent turning movement of the plug during adjustment.

7. A lap member having an expansible tubular body, a tapering seat formed therein, means carried by the body having a member adapted to engage said seat, said means including an elastic member for causing the Walls of the same to expand and enlarge the circumference of the body, and a detachable shank at one end of the body for securing the lap to a lathe chuck or similar machine.

8. In a lap, an expansible tool, a movable device cooperative therewith to expand or contract said tool as a result of its move- -ments, an elastic means exerting its tension means to limit the expanding movement of said movable device.

9. In a lap, an expansible tool comprising relatively movable parts having interior cam surfaces disposed'about the axis, an axially movable device adapted to engage said cam surfaces, an elastic member exerting its tension in such manner as to cause said movable device to engage said cam surfaces and ex pand said tool, adjustable means to limit the expanding movement of said movable device, andan adjustable means for varying the tension of the elastic member.

10- In a lap, an expansible tool comprising relatively movable parts having interior cam surfaces disposed about the axis, an axially movable device adapted to engage said cam surfaces, an elastic member exerting its tension in such manner as to cause said movable device to engage said cam surfaces and expand said tool, adjustable means to limit the expanding movement of said movable device, and an adjustable means for varying the tension of the elastic member.

11. In a lap, an expansible tool comprising relatively movable parts having interior cam surfaces disposed about the axis, an axially movable device adapted to engage said cam surfaces, said device having an axial stem protruding from one end of the tool, a spring surrounding said stem and confined between said device and the tool body so as to exert its tension to expand said tool, and a limiting stop adjustably secured to the projecting end of said stem.

12. In a lap, an expansible tool comprising relatively movable parts, elastic means exerting its tension on said relatively movable parts to expand the tool, the adjacent edges of said movable parts extending in substantial parallelism at an acute angle to the axis of the tool.

In testimony whereof We aflix our signatures.

LORENCE S. RASMUSEN. HERMAN B. CARLSON. 

